EPA’s Office of Research and Development has requested CASAC peer review of its third external draft "Integrated Science Assessment for Lead," intended to provide a synthesis and evaluation of science relevant for revising the primary (health-based) and secondary (welfare-based) standards for the national ambient air quality standards for lead. The CASAC previously reviewed the first external review draft of the Agency's Integrated Science Assessment and previously reviewed the second external review draft of the Agency's Integrated Science Assessment.

Under the Clean Air Act, EPA is required to carry out a periodic review and revision, as appropriate, of the air quality criteria and the primary and secondary standards for six criteria air pollutants, which include lead. Primary standards set limits to protect public health, including the health of "sensitive" populations such as asthmatics, children, and the elderly. Secondary standards set limits to protect public welfare, including protection against decreased visibility, damage to animals, crops, vegetation, and buildings.